US4020481A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid level alarm device
Assignee: Astemo Ltd
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Filing: 1976-01-14
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Granted: 1977-04-26
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Expires: 1996-01-14
Abstract
Abstract A fluid level alarm device which is capable of warning a person of a shortage in level of an operating fluid stored in a fluid tank and in which the critical fluid level at which an alarm signal is produced is determined with a maximized accuracy by positioning a magnetically operable reed switch, electrically connected to an alarm, within the tank at a predetermined vertical location in a manner so that, when the fluid stored in the tank is lowered below a specified level, said reed switch is magnetically closed to operate the alarm.
Inventors
- 👤 Tadao Nakagawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:42
CPC Classifications
G; G01; G01F; G01F23/00; G01F23/30; G01F23/64; G01F23/72; G01F23/74
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
278 words
A fluid level alarm device comprising a fluid tank adapted to be connected with a master cylinder, said fluid tank having an open top portion, a cap member detachably secured to said open top portion, a hollow switch cylinder integrally formed with said cap member and extending therefrom in a generally vertical direction, a float member arranged to float on an operating fluid stored in said fluid tank and fitted over said switch cylinder for vertical sliding movement relative thereto, a magnet carried by said float member, a switch base plate mounted within said switch cylinder and having a lower end abutting against the interior surface of the bottom of said switch cylinder, said plate having a pair of current paths printed on one side thereof and a respective connector terminal formed on each of said current paths in a respective predetermined fixed position, a reed switch having a pair of end terminals respectively and firmly secured to one of said connector terminals of said current paths and operable to be closed under the influence of the magnetic force exerted by said magnet when said float member falls below a certain predetermined level, a source of electrical energy, an alarm means electrically connected to said source of electrical energy, a first lead line connected at one end to one of said current paths and at the other end to said alarm means, and a second lead line connected at one end to the other of said current paths and at the other end of said source of electrical energy, both of said lead lines extending from said respective current paths through, and fixedly supported by, said cap member.
Claim 2
Dependent Claim
278 words
A fluid level alarm device comprising a fluid tank adapted to be connected with a master cylinder, said fluid tank having an open top portion, a cap member detachably secured to said open top portion, a hollow switch cylinder integrally formed with said cap member and extending therefrom in a generally vertical direction, a float member arranged to float on an operating fluid stored in said fluid tank and fitted over said switch cylinder for vertical sliding movement relative thereto, a magnet carried by said float member, a switch base plate mounted within said switch cylinder and having a lower end abutting against the interior surface of the bottom of said switch cylinder, said plate having a pair of current paths printed on one side thereof and a respective connector terminal formed on each of said current paths in a respective predetermined fixed position, a reed switch having a pair of end terminals respectively and firmly secured to one of said connector terminals of said current paths and operable to be closed under the influence of the magnetic force exerted by said magnet when said float member falls below a certain predetermined level, a source of electrical energy, an alarm means electrically connected to said source of electrical energy, a first lead line connected at one end to one of said current paths and at the other end to said alarm means, and a second lead line connected at one end to the other of said current paths and at the other end of said source of electrical energy, both of said lead lines extending from said respective current paths through, and fixedly supported by, said cap member.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-04-25 | 1980-10-25 | 1981-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-04-25 | 1984-10-25 | 1985-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-04-25 | 1988-10-25 | 1989-04-26 | $7700.00 | Window Closed / Lapsed |